The invention to a method for producing a one-piece steel piston for an internal combustion engine.
EP 452 250 A2 relates to a forging process to produce a one-piece steel piston. To create a cooling channel, an outwardly projecting circumferential shoulder is formed in the area of a top land using this process, which his assigned to a similarly circumferential recess. In a further step, the shoulder is formed over by bending to create a closed cooling channel.
A process for producing a forged piston head is known from DE 37 13 191 C1 in which one step includes the forming over or bending over of the annular section into a final position. This piston contains a cooling channel located toward the outside with a relatively small cross-section which provides only a local cooling effect for the piston and is thus inadequate over a wide area.
Furthermore, steel pistons for commercial vehicles are known in which the cooling channel is closed with a cover plate. This step is only possible with open and easily accessible cooling channels and additionally requires a great investment in mechanical machining work. Furthermore, the boring of the cooling channel on the finished component restricts design freedom. In casting technology, passenger-car steel pistons are produced experimentally using the lost-core process, in particular, a ceramic core. This process-related, complicated and cost-intensive process disadvantageously requires complex tools to produce the blanks.
Using the prior art as a point of departure, it is desirable to implement a heavy-duty, weight- and cost-optimized cooling channel piston that encloses an enlarged cooling channel.